Automatic safety draw-bar for farm-tractors.



A. J. COLWELL. AUTOMATIC SAFETY DRAW BAR FARM TRACTORS.

APPLICATION FILED APR. 30- I91]- Patented Oct. 8, 19125 2 $HEETS-SHEETI,

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A. 1. COLWELL. AUTOMATICSAFETY DRAW BAR FOR FARM TRACTORS.

APPLICATION FILED APR. 30. I9II- ldtented Oct. 8

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' Draw-Bars for Farm-Tractors, of which the ALVAH' a. ooLwsLL, 0Fnonronx, assassins AUTOMATIC SAFETY DRAW-BAR FOB FARM-TBAGTORS.

' Specification of Letters Patent.

Patented ea. s, 191s.-

Application filed e u so, 1917;. Serial No. 165,457.

To all whom it mag concern:

7 Be it known that I, ALVAH J. GoLwnLL, a

; citizen of the United States, residing at Norfolk, in the county ofMadison and State of Nebraska, have invented certain new and usefulImprovements, in Automatic Safety following is a specification,reference being had to the accompanying drawings.-

This invention relates to dra t devices,

and particularly to draw bars or draft devices used in traction engines.In the'operation of traction engines, particulahly when pulling plows orlike implements, the plows often strike a boulder, stump or otherrelatively solid obstruction and unless the traction engine stops, theplow or other implement is liable to he broken.

The general object ofthis invention is to provide means whereby thetraction engine shall be automatically stopped when the plow or otherimplement strikes an obstruction which is sufiicient to detain the plowor other implement and prevent its moving forward. i

And a further'ohject-is to provide means of this character in the "formof a longitudinally cohtra'ctible draw bar, which, when contractedapredetermined amount by the implement strikin an obstruction, willcause the actuation of t e engine stopping device.

I the following panying drawings, wherein A further object is to providea construc-.

tion of this character in which the amount of contraction of the drawbar necessary to actuate-the engine stopping device may be adjusted.

A further object of the invention is to pr o-.

vide means of the character described, wherein a predetermlnedcontraction of the draw bar will cause the completion of a short circuitthrough the ignition device of an internal combustionengine such as isused on most modern farm tractors.

i Other objects will appear in the courseor descri tion. v My-inventlonis il ustrated in the accom- Figure l 's a side elevation ot'a tractorwith a gang of'plows attached and showing my'improved draw barbetweenthe plows;

- Fig. 2 'is a side elevation of the draw bar with a portion of theelectrical. connections, :Fig. 3 is a top planv'iew of'the draw bar;

the draw bar;

Fig. l isa longitudinal sectional-view of- Fig.- 8 is a like view toFig. 7 but showing a valve directly operated by the draw bar.

Referring to these drawings, it will be seen that my improved draw barconsists of two cylindrical sections, one designated 10 and the other11, the section 11 telescoping over the section 10 and beinglongitudinally movable therealong. The section 11 is closed at one endby an end wall 12 and the sec tion 10 is closed at its-outer end by anend wall 13. These end wallsrare preferably of steel, as-is the casingformed with the sections 10 and 11 and the end-walls are securely weldedor otherwise firmly connected to the tubular sections 10 and 11.

Disposed within thecasing formed by the sections 10 and 11 is arelatively heavy coiled spring 14, one end of which bears against thecap or end wall 13, the other end of which bears against the cap or endwall 12. Extending longitudinally through the casing is a draft iron 15having two legs, which have sliding engagement with the head 12 andwhich are attached to the wall 13 by being headed over onto this wall orhead. At the other end of the device is the draft iron 16 having twoparallel legs each having sliding engagement through the wall l3 andeach extending longitudinally through tractor'that if the implement bestopped on its onward courseand the tractor continues to moveforward,.the draft iron 16 will cause the end wall 12 to move toward theend wall operation, of course, would occur if the tractor was attachedto the draft iron 15 and the implement was attached to the draft iron16.

' Mounted upon the section 11, and movable therewith, is a contact bar17 .having one 13 thus compressing the spring. The same 7 be shortcircuited, thus extremity slightly turned upward as at, 18. This contactbar is held upon the tubular section 11 in any suitable manner, as bythe clamps 19, these clamps being so constructed that the contact barmaybeshiftably adjusted through the clamps so as to project to a greateror less distance beyond the inner end of the section 11.. Asillustrated, these clamps are formed with straps 20, which arch over thecontact bar and through these straps pass set screws 21 held in en-'gagement with the contact bar by-means of set nuts 22. I do not, ofcourse, Wish to be limited to this particular method of adjustablyclamping the contact her.

Mounted upon the section 10 and illustrated as mounted upon the end wall13 is a block 23 of insulating material and mounted upon this block is acontact member 24., which may be made of brass or any other electricallyconductive material, and which is held in place upon the insulatingblock by means of the screws 25. The extremity of this contact member 24is downwardly inclined so that it may have'electrical engagement withthe upwardly turned end 18 of the contact bar 17 when the two sectionsare drawn in proper co-active relation to each other. Electricallyconnectedto the contact plate 2 1,'as by' means of the screws 25, is aconductor 26 leading to an electrical switch 27 from which switch aconductor 28 leads to the magneto or other equivalent device B on theengine, so that when the contact plates 24 and 17 are in engagement witheach other, the magneto or equivalent device will preventing ignition ofthe charge in the engine and stopping the motor and tractor.

implement.

The operation of the construction, as

' above described, will be. obvious. In case breakln of parts and itwill be seen that the power of the motor is instantly cut off beforeexcessive strains are produced by the tractor plow after the obstructionis engaged by the If for any reason this electric cut-out is not wantedfor use for short periods of time, the switch 27 may be opened so thatno current can pass through the short circuit conductors 28 and 26 andthus the timing device or magneto will not be short circuited in casethe contact members 17 and 24 are pulled into electrical engagement witheach other.

The contact bar or member 17 is made adjustable so that any desiredcompression of the spring can be obtained before the contact takes placeto stopthe motor so that the resistance formed by different implementsor the differences in the resistance formed by one or more plows may becompensated for. While preferably the spring of the draw bar will beinclosed within a tubular body comprising two telescopic sections, itwill be understood that it is within the purview of my invention to formthis draw bar in any suitable manner and without the use of theintersecting casing.

f a steam engine is used, instead of an internal combustion engine ormotor, various means may be provided for stopping the engine when thespring is compressed to a predetermined amount. Thus in Fig. 7 I

ave illustrated a solenoid 29, operatively connected to the throttlevalve C of a steam tractor engine, this magnet 29 being connected incircuit with a storage battery 30. or other suitable source ofelectricity and the contact members 17 and 24-being used as a circuitcloser in said circuit so that When the spring is compressed,apredetermined amount, these contact members will electrically engageeach other, close the circuit through the magnet and the storagebatteries and thereby shift the throttle valve to cut ofl the passage ofsteam to the cylinders of the engine.

It is obvious also that a purely mechanical device may be used for thispurpose, actuated, as illustrated in Fig. 8, by a member 17 mounted uponone section of the draw bar and shiftably engaging a movable member 24mounted on the'other section of the draw bar which in turn isoperatively connected to the throttle valve C. I, therefore, do not-wishto limit myself to the use of purely electrical means for stopping theengine as mechanical means may be used for the same purpose, nor do Iwish to limit myself to short circuiting the ignition system of aninternal combustion engine.

Preferably the barrel of the spring 14 as,, for'instance, the barrelsection 10, is calibrated to indicate the pull in pounds on the drawbar, as indicated in Fig. 2. This calibration is particularly convenientin that itaffords means for determining the draw bar pull of the tractorat all times and further provides means whereby the contact bar 17 inFig. 2 may be properly set.

Having described my invention, what I claim is 1. The combination with atractor, a motor therefor, and means for sto ping the motor, of a draftdevice comprlsing coacting elements movable with relation to each other,one connected to the tractor and the other to the implement being movedthereby, a spring resisting movement of said elements under strain, anda member operatively connected to one of sai'delements and positively.

movable .therewith in o posite directions, said member being norma 1yheld out of engagement with the motor stopping means by the action ofthe spring but engageable with said motor stopping means when theresistance to the movement of the implement by the tractor reaches acertain point, and means for support ng said member whereby it may bead'usted along its line of travel toward or rom the motorstopping-"means to thereby adjustably predetermine the instant ofactuation of the motor stopping means.

2. The combination with a tractona motor therefor, and means forstopping the mo tor, of a draft device comprising coacting.

elements longitudinally movable with rela tion to each other, oneconnected tothe tractor and the other to' 'the implement being drawnthereby, means yieldingly resisting the movement of the elements understrain,

'a motor stopping means, and a member mounted upon and positivelymovable with one of said elements for movement with the element towardor from the motor stopping means, said member being adjustableindependent-1y of the element upon which it is mounted toward or fromthe motor stopping means to thereby control the instant of actuation ofthe motor stopping means.

3. -The combination with a'tractor, a motor thereon, and means forstopping the motor, of a draft device comprising coacting sections,longitudinally movable with relation to each other, one connected to thetractor and the other to the implement being drawn thereby, a coiledcompression spring resisting longitudinal movement of the sections understrain, and means for automatically actuating said motor stopping meanscomprising a member mounted upon the outermost of said sections andmovable in opposite directions therewith, saidmemher belng.longitudinally adjustable upon the section to which it is attached inthe direction of its travel, to thereby control the instant of actuationof said engine stopping means.

4. A drawbar for connecting tractors to implements to be drawn therebycomprising coactin elements having sliding engagement with each other,one adapted to be connected to the tractor and the other to the objectto be drawn, a spring yieldingly resisting movemenif'bf" the elementsunder strain, and motor stopping members, each mounted on one of saidelements for movement therewith in opposite directions and adapted to bebrought into operative engagement with each other upon a redeterminedmovement of the elements un er strain. 7

, 5 The combination with a tractor, a' motor therefor and means forstopping the motor including an electrical conductor, of a draftfdevicecomprising coacting members movement of said members,an electricalconpredetermined other, one connected to the tractor and theother to theimplement to be drawn thereby, a spring yieldingly resistinglongitudinal tact operatively mounted upon one of said members, and anelectrical contact operatively mounted upon the other member andconnected to said conductor, a relative movement of said members againstthe force of the spring bringing said contacts in electrical engagementto thereby stop the motor. 6. The combination with tractor and aninternal combustion motor having an ignition system, of a draft devicecomprising coacting members longitudinally movable with relation .toeach other one connected to the tractor and the other to an implement tobe drawn thereby, a spring yieldingly resisting relative movement ofthesaid members in one direction, and means for automaticallyshort-circuiting the ignition system comprising contacts operativelymounted upon said members and normally held in spaced relation by thespring, one of said contacts being electrically connected to theignition system of the engine, said contacts being brought intoelectrical engagement upon a compression of the spring due to resistanceoflered by the implement being drawn. I 7. A draft device of thecharacter described comprising coacting members longitudinally movablewith relation 'to each other, a spring resisting said movementtelescopic cylinders mounted upon said members and housing the springand mov- .able with the members, and electrical contacts mounted uponsaid cylinders extetive engagement with each other by'said spring, butbrought into electrical engagement with each other by the movements ofthe members against the force of said spring.

8. A draft device of .the character described comprising coactingmembers longitudinallymovable with relation to each! other,

a spring resisting said movement, cylinders res ectively mounted uponsaid members an connected therewith, said cylinders having telescopicengagement with each other and housing the spring and said members, andelectrical contacts mounted upon A said cylinders and normally held outof op erative engagement with each other by the spring but brought intoelectrical en agement with each other by a movement 0 said membersagainst the force of said spring, said contacts being relativelyadjustable toward or from each other upon said members whereby tocontrol the instant of engagement between said'contacts.

9. A draft device of the character described comprisin' longitudinallyextending draft irons, each raft iron at its end having a head throughwhich the other draft iron slidingly passes, whereby a movement of thedraft irons away from each other will draw the heads toward each other,a compression a upon the respective heads and mova e into ctricalengagement with each other upon a predetermined movement of the headstoward each other.

10. A draft device of the character described comprisin a pair oflongitudinally extending paralleidraft irons, a head carried upon eachdraft iron at the extremity thereof and through which head the otherdraft iron slidingly passes, coacting telescopic casin sections mountedupon the heads, a coi spring disposed within said casing section andbearing against the heads and resisting a movement of the heads towardeach other, and electrical contact members operatively supported uponeach of said casing sections and movable into electrical engagement witheach other upon a predetermined movement of the heads toward each othera inst the force of said spring.

11. A dra ried upon each draft iron at the extremity thereof and throughwhich head the other engagement with each other upon a predetermmedmovement of the heads toward each other against the force of saidspring, one of said contact members being adjustably mounted forlongitudinal movement toward or from the other contact member to therebycontrol the instant of engagement between the contact members.

12. The combination with a traction engine having an internal combustionmotor including an electrically operated device, of a draft deviceincluding two parallel draft irons disposed in overlapping relation, oneof said draft irons being connected to the traction engine and the otherto the article to be drawn, said draft irons each having a head throughwhich the other draft iron slidingly passes, a coiled compression springsurrounding the draft irons and bearing against the heads and resistingmovement of the heads toward each other, tubular sections mounted uponthe respective heads and having telescopic engagement with each other, acontact mounted upon one of said heads, a contact mounted upon theopposite tubular section and adjustable longitudidevice of the characterde-' scribed comprisin a pair of longitudinally extending paralle draftirons, a head carnallythereon, a conductorattached to the first namedcontact and extending to the said magneto, to short-circuit the same,when the contacts are brought into electrical engagement with eachother, and a switch in the circuit between the contact and the magnetofor breaking said circuit.

13. The combination with a tractor and a motor therefor, of a draftdevice comprisin coacting elements movable toward and rom each other,one connected to the tractor and the other ada ted to be connected to animplement being rawn thereby, a spring resisting movement of theelements under strain, a member for stop ing the motor, and an actuatingmember t erefor operatively connected to one of said elements andmovable therewith in opposite directions, said actuating member beingnormally disposed out of engagement with the motor stopping member butshiftable into actuating engage- -ment therewith by a relative movementof the elements under a predetermined strain and shiftable out ofengagement therewith by a relative movement of the said elements in theopposite direction-under the action of the spring.

14. A draft device of the character described comprising longitudinallyextending draft irons, each having a head through which the other draftiron yieldingly passes, whereby a movement of the draft irons away fromeach other will draw the heads toward each other, between said heads andresisting said ina compression spring disposed ward movement of theheads, and members operatively supported upon said heads and normallyheld in spaced relation to each other b the force of said spring, saidmembers w en engaged with each other being adapted to stop the operationof a motor, one of said members being longitudinally adjustable towardor from the other member to thereby control the instant of engagement ofsaid members with each other.

15. A draft device of the character dc scribed comprising a pair oflongitudinally extending parallel draft irons having sliding engagementwith each other, a head carried upon each draft iron at the extremitythereof and through which head the other draft iron slidingly passes,coacting telescopic' casing sections .mounted upon the heads, a coiledspring disposed within said casing sections and bearing against theheads and yieldingly resisting a movement of the heads toward eachother, clamps mounted upon one of said tubular casing sections, and anactuating bar mounted in said clamps and adjustable therethroughlongitudinally with relation to the casing section upon which it ismounted.

16. A draft device of the character described comprising coactingelements longitudinally movable with relation to each other, one oftheseelements being adapted to be operatively connected to a tractor and,the other to an implement being moved thereby, a sprin' resistinglongitudmal lationhto the element 'upon which it is mounted, and acoacting actuating member disposed in the path of movement of the;

first named member, normally in spaced re-" lation thereto and beingengaged thereby when the said elements arelongitudinally moved relativeto each other against the 15 force of the spring.

In testimonywhereof I hereunto affix mysignature in the presence of twowitnesses. w

ALVAH J. COLWELL.

Witnesses! p L. P. PA EWALK; A. F; WENTWORTH.

